Sterilizer door



Feb. 7, 1961 H. c. JENNINGS, JR

STERILIZER DOOR Filed Sept. 28, 1959 IN VEN TOR.

STERILIZER DOOR Harry C. Jennings, Jr., Los Angeles, Calif., assignor toEverest & Jennings, Inc., Los Angeles, Calif., a corporation ofCalifornia Filed Sept. 28, 1959, Ser. No. 842,986 2 Claims. (Cl.220-553) This invention relates to improvements in doors for sterilizersand other vessels designed to contain fluids under high pressures.

Explanatory of the present invention, sterilizers have heretofore beenprovided which have openable doors through which articles to besterilizedcan be placed in the sterilizer. When the sterilizer has beenfilled with the articles to be sterilized the door is closed and steamis either supplied to the sterilizer or generated therein and maintainedtherein under high pressure the required time to accomplishsterilization. Thereafter, the pressure is reduced to atmosphericpressure or substantially so and the door opened and the sterilizedarticles removed from the sterilizer.

It frequently occurs, however, that the door is opened prior to the timethat the steam pressure within the sterilizer has been reduced toatmospheric pressure with the result that the door may be thrown openviolently and the escaping steam produces scalds or burns.

An object of the present invention is to provide a door for sterilizersand similar pressure vessels which is so designed that it is impossibleto open the door until the pressure within the vessel has been reducedto atmospheric pressure or substantially so. As long as pressure remainsin the sterilizer of any substantial magnitude this pressure beingeffective on the door prevents the turning of its re lease mechanisminto a releasing position. However, whenever the pressure within thesterilizer reaches atmospheric pressure or substantially so, the doorcan then be opened for the admission of articles to be sterilized or theremoval of sterilized articles from the sterilizer.

With the foregoing and other objects in view, which will be mademanifest in the following detailed description and specifically pointedout in the appended claims, reference is bad to the accompanyingdrawings for an illustrative embodiment of the invention, wherein:

Figure 1 is a view in front elevation of the sterilizer door, the doorbeing shown in its closed position;

Fig. 2 is a horizontal section taken substantially upon the line 2-2upon Fig. 1 in the direction indicated;

Fig. 3 is a vertical section taken substantially upon the line 33 uponFig. 1 in the direction indicated;

Fig. 4 is a partial view in vertical section illustrating details of thekeeper for the door; and

Fig. 5 is a perspective view illustrating a portion of the latch for thedoor.

Referring to the accompanying drawings wherein similar referencecharacters designate similar parts throughout, indicates the door frameof a sterilizer. At one side of the door frame there is a knuckle 11above and below which there are ears 12 and 13 on a bar 14 which ispivotally connected to the knuckle by a pivot pin 15 enabling the bar 14to be swung between door-opening and door-closing positions.

The door for the sterilizer is indicated at 16 and has a boss 17 on itsback which is pivotally connected to the bar 14 by means of a pivot pin18. This pivotal connecnitecl States I atent tion enables the door toself-adjust itself with relation to a seat 19 on the door frame.

Near the marginal edges of the door 16 there is a channel designed topartially receive a resilient seal 20. This seal is approximatelyV-shaped in cross-section having a flange 21 designed to resilientlypress against the seat 19. The seal in effect performs a doublefunction. One function of the seal is to prevent leakage around the doorbetween the door and its seat 19. The other function of the seal is toyieldably urge the door 16 outwardly or away from its seat 19.

In accordance with the present invention, a keeper 22 is arranged on thedoor frame 10 on the opposite side thereof-from knuckle 11. This keeperhas an inclined groove 23 formed on its inner face presenting a surfaceor shoulder 24 that is engageable by the latch on the bar 14 which holdsthe door in closed position. The latch is in the form of a rocker shaft25 that is rotatably mounted in the swinging end of the bar 14 forrotation about an axis extending generally in the direction of swing ofthe swinging end of bar 14, and held against axial movement between ashoulder 26 and a collar 27 thereon. This rocker shaft can be rotated bymeans of a handle'28 through approximately A pin 29 on the rocker shaftis engageable with upper and lower pins 30 and 31 on the bar 14 at eachof its extreme positions of rotation.

On the inner end of the rocker shaft 25 there is formed a partial orhalf-thread or helical cam 32. This partial thread or helical camextends approximately one-half way around the rocker shaft 25. At oneend of the half-thread or helical cam it is thickened as at 33 toprovide a shoulder 34 engageable with the inner face of the keeper 22 asillustrated on Fig. 2.

When the door 16 is in closed position as illustrated, fluid pressureexisting in the sterilizer is elfective on the inner face of the door.This pressure is also effective on the flange 21 of the rubber seal topress this flange into firm engagement with the seat 19 and thus preventleakage around the edges of the door. The pressure that is elfective onthe inner face of the door 16 urges the door outwardly with aconsiderable force, pressing the half-thread or helical cam 32 into firmengagement with the shoulder 24 on the keeper 22. While this conditioncontinues to exist the engagement of the shoulder 34 with the inner faceof the keeper 22 prevents rotation of the rocker shaft 25 from thelatching position shown into releasing position. However, when thepressure within the sterilizer is reduced to atmospheric pressure orsubstantially so, it is then possible to press the bar 14 and the door16 toward the seat 19, thus compressing the yieldable seal 20sufficiently to cause the shoulder 34 to clear the top of the keeper 22and to enter the top of the inclined groove 23. Once that the thickenedportion 33 on the rotary latch has entered the inclined groove 23 on thekeeper it is then possible to continue rotation of the rotary latch 25by the handle 28 through approximately 180 and thus position the blankside of the latch opposite the keeper. This releases or detaches the bar14 from the keeper and the door 16, together with the bar 14 can beswung into open position.

In closing the sterilizer the door 16 and the bar 14 are swung intoclosed position, and in so doing, the door 16 centralizes itself withrespect to its seat 19 by virtue of the pivotal connection at 18 bypressing the door inwardly and thus compressing the rubber seal 20slightly. The thickened portion 33 on the half-thread can be caused toenter the bottom of the inclined groove 23 on the keeper. The rotarylatch 25 can then be rotated by its handle 28 until the shoulder 34clears the top of the shoulder 24 and on snapping into the positionshown in Fig. 2, reverse rotation of the latch cannot be accomplishedwithout pressing the door 16 inwardly the required distance to compressthe seat 20 and enable the shoulder 34 tov clear the upper portion ofthe shoulder 24 and enter the groove. As long as pressure materiallyabove atmospheric is effective, on the door 16 this inward movement anddeformation of the seal 20 is impossible. Consequently, as long aspressure exists in the sterilizer it is impossible to accid'entally orinadvertently open the door. It is only when pressure in the sterilizeris reduced to atmospheric pressure or approximately so that it ispossible to press the door 16 inwardly the necessary distance to clearthe shoulder 34.

When pressure in the sterilizer is only slightly above atmosphericpressure or the sterilizer contains what is sometimes referred to asresidual pressure, it might be possible topress the; door inwardly asufficient distance to enable the shoulder 34 to clearthe upper portionof the shoulder 24 and enter the groove. However, even when this ispossible the movement of the shoulder 34 down the inclined groove 23:enables the seal 20 to disengage the seat 19 before the handle hascompleted its 180 turn to a releasing position. This. releases anyremaining or residual pressure in the chamber around the marginal edgesof the door before the door can be blown open by this remainingpressure.

Various changes may be made in the details of construction withoutdeparting from the spirit and scope of the invention as defined by theappended claims.

I claim:

1. A door for a pressure vessel adapted to contain a hold underpressure, said door having a resilient sealing means around its edgesurging the door to open and seal ing the door against leakage around itsedges, a swingable bar on which the door is pivotally mounted, a latchrotatably mounted on the swinging end of the bar for rotation about anaxis extending generally in the direction of swing of the swinging endof the bar, a keeper engageab le by thelatch to releasably hold the oarand door in doorclosing position, said latch having a helical camextending partially around the inner end of the latch engageable withthe keeper to hold the bar and door in closed position and on rotationof the latch to disengage the keeper whereby the door may be opened,said cam having a shoulder adjacent one end thereof engageable with thekeeper and preventing rotation of the latch into keeperdisengagingposition unless it is possible to force the door inwardly in the absenceof material pressure in the vessel and compress the sealing means.

2. A door for a pressure vessel adapted to contain a fluid underpressure, said door having, a resilient sealing means around its edgesurging the door to open and sealing the door against leakage around itsedges, 2. swingable bar on which the door is pivotally mounted, a latchrotatably mounted on the swingingend of the bar for rotation about anaxis extending generally in the direction of swing of the swinging endof the bar, a keeper engageable by the latch to releasably hold the barand door in door-closing position, said keeper having a downwardly andforwardly inclined groove therein, said latch having a partial helicalcam on the inner end thereof extending partially around the inner end ofthe latch adapted to enter said groove in the keeper to hold the bar anddoor in closed position and on rotation of the latch to disengage thekeeper whereby the door may be opened, said cam having a shoulderadjacent one end thereof engageable with the keeper and preventingrotation of the latch into keeperdisengaging position unless it ispossible to force the door inwardly in the absence of material pressurein the vessel and compress the sealing means.

References Cited in the file of this patent UNITED STATES PATENTS

